The effects of the interfacial parameters (interface/matrix modulus ratio, interface Poisson ratio and interface volume fraction) and the structural parameters (particulate volume fraction, particulate shape, arrangement pattern and dimensional variance mode) on the elastic modulus of SiCp/6066Al composites were calculated and analyzed. The results showed that component and interface performance significantly influenced the elastic modulus of the composite; but the particulate shape, arrangement pattern and dimensional variance mode were found to have little influence. This means that the effect of the above structural parameters can be negligible. The optimal approach to enhance the elastic modulus and specific elongation of a composite is to improve the interfacial bonding of the particulate. Optimal results are obtained when the interface modulus is 20% ~ 30% of the matrix modulus.